She wakes up to Ron whispering the same words over and over and Harry repeating them back, a sound as familiar to her as the thump of her own overloud heart. Too many nights in the common room before exams, cramming charms and stumbling over the pronunciation, but right now she recognises real fear behind Harry's exhaustion and she rolls over to look at them.
"Ron, mate." Harry's face is lit with concern and pale wandlight, the edges of his limbs swallowed by the tent's shadows. "Enough. Come on."
This is familiar too; Hermione is already sitting up and rubbing her eyes because her body anticipates the cue.
"If I can't sleep, I might as well be doing something useful." Ron makes as though to lift his wand again and Harry reaches out with effortless speed to take hold of his wrist, trap it like a Snitch and hold it steady.
"Enough," he says again, with fond and quiet finality. It's Hermione's cue, but she forgets herself for a moment and stays where she is, groping within herself for boundaries, barrier spells, anything to limit the sudden enormity of love overflowing in her chest and thumping to a roar in her ears. Wandlight reflected in Harry's glasses and the way Ron's body shivers and then subsides, grateful, within the circle of his fingers. Too much.
Hermione reins in the glow until her throat is clear enough to speak. "I could make cocoa," she suggests, as she often suggests, and Harry's tired face flickers with something: perhaps gratitude and perhaps more.
"Nah," Ron says, his eyes moving to her face with a smile. "Ta, Hermione, but I think I'm ready to get some sleep."
"Yes," Harry agrees after a moment, and releases Ron's wand hand.
She imagines that she is a monitoring charm in human form, that if anything happened to either of them then she would know simply through the contact of her palms against theirs; that by lying between them and linking them she can keep them from harm. It's a nice fantasy. She's always fought to protect them and she's always been proven fallible and it's always, always felt like a personal insult that the world keeps on wounding the people she loves. That her love is inadequate and cannot work any magic of its own, even when she knows -- she knows, and she presses Harry's fingers between hers -- that love can save a life.
But tonight her heart is boundless and glowing like dragonfire; tonight she can pretend that when the battle comes, love might be enough.